Forensic investigation of pedestrian bridge that collapsed during construction. Field research, design and code compliance review, sample testing, structural analysis, report.
Weidlinger Associates was retained by the NY State Department of Transportation (NYSDOT) to determine the cause of the construction collapse of the Marcy Pedestrian Bridge, in Oneida County, during placement of the concrete deck slab. The accident occurred when all the reinforcement, forms, construction equipment and personnel were on the deck, and more than half (105 feet) of the concrete had been poured and was still mostly wet. Weidlinger determined that global torsional buckling was responsible for the failure, specifically the extremely low torsional stiffness during the deck pouring and prior to its curing. Weidlinger recommended clarifying the codes for this type of bridge and requiring additional structural safeguards during construction unless analysis proved them unnecessary. Weidlinger's scope of work included field investigation, data collection and evaluation, review of the existing bridge design for conformance to design codes and standards, and evaluation of relevant NYSDOT design and construction procedures. The firm performed a detailed three-phase structural analysis that included both linear elastic and nonlinear computer modeling. Steel samples taken from the collapsed bridge were also tested and evaluated, and interim and final reports were submitted to the department.
Completion Date: 2003 Location: Marcy, New York Owner or Client: NYS Department of Transportation Prime Consultant(s): WAI Prime